M4T CV Table





TCS M4T [Rev 52] – CV Summary
(Version 52 production begun April 2010!)
CV # Default Value Description
3 5 Acceleration
4 5 Deceleration
34 16 Remap the yellow wire (F0R) to FUNCTION 3
49 32 Headlight control set to non-directional
50 46 Rear light set to brake feature non-directional
61 9 Enables BEMF and Brake function control (See below)
64 6 Sets dim values for LEDs
126 5 Brake deceleration value
137 128 Brake off delay fine adjustment
138 16 Brake off delay coarse adjustment
139 128 Remap value for brake function. 128 = FUNCTION 6
Figure 1 - TABLE 1 This TCS M4T decoder was specifically designed for any HO scale single end PCC car equipped with brake lights. The M4T decoder includes a modified brake light feature that allows for prototypical brake lights when decelerating and stopping. The brake lights are activated or deactivated by FUNCTION 3. Additionally we have added function control of braking via FUNCTION 6 to allow you to recreate the regular stops and starts of a prototype streetcar without constant adjusting the throttle. Seasoned DCC trolley modelers may find ways to adapt the M4T decoder to other streetcars, trams and light rail vehicles. Note that the default value for CV 61 in the decoder is 9. With this value, the decoder is set-up for the traditional, as originally manufactured, PCC car, with no automotive type tail lights. The F-line PCC cars, series 1050-1063, were acquired from Philadelphia in 1992 and rebuilt by Morrison Knudsen for service in San Francisco. These cars, unlike traditional PCC cars, are equipped with rear taillights, similar to an automobile, in addition to brake lights. To activate the taillight function for a San Francisco F-line PCC, change CV 61 from 9 to 137. The brake feature becomes fully operational when pressing FUNCTION 6. When the car is stopped, you MUST press FUNCTION 6 again to restart the car. The braking function can be assigned to any function with a use of our remapping technique as shown in Table 2 below. Example: If you desire the automatic brake function to be operational with FUNCTION 4, the value of 32 needs to be placed into CV139.
CV# Function # Value
139 0 1 or 2
139 1 4
139 2 8
139 3 16
139 4 32
139 5 64
139 6 128
Figure 2 - TABLE 2 The brake light can be turned ON/OFF with FUNCTION 3 by default. You can remap it to any other function with the technique shown above. For that you need to use CV 34. See Table 3 below:
CV# Function # Value
34 0 1 or 2
34 1 4
34 2 8
34 3 16
34 4 32
34 5 64
34 6 128
Figure 3 - TABLE 3 Example: If you desire brake lights to be operational with FUNCTION 5, the value of 64 needs to be placed into CV34. CV 137 will make fine changes to the period of time between braking and the brake light going off. CV 138 will make coarse changes to the period of time between braking and the brake light going off. CV 126 will adjust how slowly the trolley decelerates. This value is used only when the function control of braking is applied. CV 3 is responsible for acceleration after the brake is released. CV 4 determines how long it will take for the trolley to slow down to the full stop after the brake is applied. CV49 controls the headlight and the rear taillight and is set to the value of 32 by default. This is the non-directional mode, which means anytime the FUNCTION 0 is pressed the headlight and taillights will go ON/OFF. If by any chance you got to the point where the trolley behaves in unexpected manner, place the value of 2 into CV8 that will execute the factory reset (for factory resettable values see the table number 1 on the beginning of this article.) *PCC (President’s Conference Committee). The cars were designed by this group of electric railway representatives beginning in 1929 to compete with rubber-tired vehicles. GLH M4T – 5-4-10 [5201-5206]
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